The present invention relates to a body structure for vehicles such as automobiles and, more particularly, to a body structure capable of effectively absorbing impact loads upon a collision of vehicles.
As is well known, the body structure for vehicles such as automobiles has been energetically improved and devised with the aim of enhancing the passenger-protecting performance at a collision of vehicles.
In recent years, particularly, it has been desired to enhance the passenger-protecting performance of a vehicle upon a collision sideways (so-called side collision) in addition to collisions in the front-and-rear directions of the vehicle, more intensely than it has been conventionally.
Conventionally, enhancement in the passenger-protecting performance at collisions of vehicles as mentioned above would generally be implemented by devising the individual frame members around the vehicle interior, their reinforcing members and the like.
For example, U.S. Pat. No. 5,242,209 (corresponding Japanese Application: Japanese Utility Model Laid-Open Publication No. 5-10167) discloses a structure showing the relationship among a reinforcing member for the center pillar, a reinforcing member for the side sill and cross members. Like this, with regard to structures of the so-called monocoque body, individual reinforcing members for the individual parts of the vehicle body are conventionally known.
However, as to how the passengers in the vehicle interior are effectively protected as a whole of the vehicle against various types of collisions (front collisions, rear collisions, side collisions or rollovers etc.), there have been proposed no concrete measures. Instead, structures provided for individual types of collisions are adopted independently for the individual parts. This would lead to a considerable increase in the weight of the whole vehicle.
On the other hand, there has been a desire that increase in the vehicle weight be suppressed as much as possible in terms of the maintenance and improvement of running performance, fuel performance and the like. With such measures as individual frame members and their reinforcement members as would be in the prior art, it has been quite hard to satisfy, at high level, both demands of the improvement in the passenger-protecting performance at collisions of vehicles and the suppression of increases in the vehicle weight.
Also, as the side sill of a closed-in-cross-section that constitutes the lower side part of an automobile body, there has conventionally been known one which is composed of a side sill outer and a side sill inner extending in the front-and-rear direction of the automobile body, and which is reinforced by a side sill reinforcement interposed between the side sill outer and the side sill inner (see Japanese Utility Model Laid-Open Publication HEI 6-6173).
However, the conventional side sill reinforcement would only be interveniently provided fragmentarily at appropriate places of the side sills in the front-and-rear direction of the body. Therefore, cross sectional deformation of the side sills due to side-collision loads cannot be effectively suppressed and, in particular, cross sectional deformation of the side sills due to offset-collision loads cannot be effectively suppressed, either, as problems.
Furthermore, there has been a problem that cross sectional deformation of the center pillar due to side-collision loads cannot be effectively suppressed.